Sun Microsystems, Inc.

Lynn Warriner

Claude R Gauthier

Brian W Amick

Tri K Tran

A SSTL memory interface pre-driver stage that uses a voltage regulator to generate a 'virtual' ground reference voltage is provided. The 'virtual' ground voltage reference, being greater than a zero volt ground voltage, allows low voltage transistors to be used, thereby improving interface performance and decreasing system power consumption. The pre-driver stage uses a biasing circuit to bias the voltage regulator, formed by a transistor arranged in a source follower configuration, to generate the &#x2018;virtual&#x2019; ground reference voltage off which a voltage translator stage of the pre-driver stage operates to generate an output of the pre-driver stage.

SSTL pull-up pre-driver design using regulated power supply

A SSTL interface voltage translator that uses dynamic biasing to translate an input signal to an output signal is provided. The voltage translator uses a first device that, dependent on a first bias signal, causes the output signal to be pulled down, where the first bias signal is dependent on the input signal. The voltage translator also uses a second device that, dependent on a second bias signal, causes the output signal to be pulled up, where the second bias signal is dependent on the input signal.

SSTL voltage translator with dynamic biasing

A cascode SSTL output buffer using a source follower circuit includes a biasing circuit arranged to generate a first bias signal. The source follower circuit is responsive to the first bias signal and generates a second bias signal which is then used by a cascode circuit that receives an input signal to the SSTL output buffer to drive an output signal from the SSTL output buffer.

Cascode SSTL output buffer using source followers

A SSTL memory interface pre-driver stage that uses a voltage regulator to generate a 'virtual' supply is provided. The 'virtual' supply, being lower than a power supply voltage of the pre-driver stage, allows low voltage transistors to be used, thereby improving interface performance and decreasing system power consumption. The pre-driver stage uses a biasing circuit to bias the voltage regulator, formed by a transistor arranged in a source follower configuration, to generate the &lsquo;virtual&rsquo; supply off which a voltage translator stage of the pre-driver stage operates to generate an output of the pre-driver stage.

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Round Rock, TX, United States of America

Lynn Warriner